audioguru2
- Apr 6, 2004
- 12,026
- Joined
- Apr 6, 2004
- Messages
- 12,026
Hi Nolram,
I installed, programmed and fixed pbx and key telephone systems.
The very old ones used stepper switches and were simple. The last key systems I worked on in the '80's used a processor in each phone, on each card then an overall processor.
Customers' offices were used as beta test sites for new models and they frequently messed-up.
One new model had an intermittent system reset, dropping all connections. I discovered that it occured when an incoming call rang a line at exactly the same time someone used that line to call out. The Japanese engineers couldn't reproduce the problem in Japan, so came over here to see how I do it! They still couldn't get the timing syncronised like me.
Those systems were 20 years ago and were very sophistocated. Modern systems are even more integrated, using ICs designed for them. I don't think a single person could design one, it would take a team of emgineers.
In the '90's I installed, programmed and fixed tele-conferencing systems, working for a manufacturer. Some systems used thousands of telephone lines and were controlled by pc's. The systems were also extremely complicated and used custom-made parts and dsp.
Even simple little full-duplex speakerphones and boardroom tele-conferencing systems had custom-made parts and a program for their dsp. Defective ones weren't repaired, they were thrown away. ;D
I installed, programmed and fixed pbx and key telephone systems.
The very old ones used stepper switches and were simple. The last key systems I worked on in the '80's used a processor in each phone, on each card then an overall processor.
Customers' offices were used as beta test sites for new models and they frequently messed-up.
One new model had an intermittent system reset, dropping all connections. I discovered that it occured when an incoming call rang a line at exactly the same time someone used that line to call out. The Japanese engineers couldn't reproduce the problem in Japan, so came over here to see how I do it! They still couldn't get the timing syncronised like me.
Those systems were 20 years ago and were very sophistocated. Modern systems are even more integrated, using ICs designed for them. I don't think a single person could design one, it would take a team of emgineers.
In the '90's I installed, programmed and fixed tele-conferencing systems, working for a manufacturer. Some systems used thousands of telephone lines and were controlled by pc's. The systems were also extremely complicated and used custom-made parts and dsp.
Even simple little full-duplex speakerphones and boardroom tele-conferencing systems had custom-made parts and a program for their dsp. Defective ones weren't repaired, they were thrown away. ;D